/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.index.analysis;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.DelegatingAnalyzerWrapper;
import org.opensearch.common.collect.CopyOnWriteHashMap;

import java.util.Map;

/**
 * Analysis chain for field names
 *
 * @opensearch.internal
 */
public final class FieldNameAnalyzer extends DelegatingAnalyzerWrapper {

    private final Map<String, Analyzer> analyzers;

    public FieldNameAnalyzer(Map<String, Analyzer> analyzers) {
        super(Analyzer.PER_FIELD_REUSE_STRATEGY);
        this.analyzers = CopyOnWriteHashMap.copyOf(analyzers);
    }

    public Map<String, Analyzer> analyzers() {
        return analyzers;
    }

    @Override
    protected Analyzer getWrappedAnalyzer(String fieldName) {
        Analyzer analyzer = analyzers.get(fieldName);
        if (analyzer != null) {
            return analyzer;
        }
        // Don't be lenient here and return the default analyzer
        // Fields need to be explicitly added
        throw new IllegalArgumentException("Field [" + fieldName + "] has no associated analyzer");
    }
}
